Hydrogel based multianalyte microsensor arrays for metabolic monitoring

This thesis describes the design and assembly process optimization of smart hydrogel based micropressure sensor arrays used for metabolic monitoring. Surface, electrical and pressure characterizations were performed on the sensor arrays. An assembly process was developed to integrate the sensor arrays with the hydrogels. Micropressure sensor arrays with both pH sensitive hydrogels and glucose sensitive hydrogels were assembled and tested in vitro in phosphate buffered saline. Sensor arrays were also tested in vitro for stability analysis.;Response times of 10 minutes for swelling cycle and 8 minutes for shrinking cycle were obtained for pH sensitive hydrogel based sensor arrays and 11 minutes for swelling cycle and 5 minutes for shrinking cycle were obtained for glucose sensitive hydrogel based sensor arrays. Such low response times were obtained using hydrogel based pressure sensors to detect glucose for the first time to our knowledge. Sensitivities of pH sensitive hydrogel based sensors were calculated to be 220 mV/V-M, 149 mV/V-M and 62 mV/V-M for pressure sensor diaphragm sizes of 1.5 X 1.5 mm2, 1.25 X 1.25 mm2 and 1 X 1 mm2, respectively. Sensitivities for glucose sensitive hydrogel based sensors were determined as 203 mV/V-M, 213 mV/V-M and 74 mV/V-M for diaphragm sizes of 1.5 X 1.5 mm2, 1.25 X 1.25 mm 2 and 1 X 1 mm2, respectively. Stability experiments performed on the sensor arrays with pH hydrogels have been found to last for over 400 hours.